Simulation Study of a Low ON-State Voltage and Saturation Current TCIGBT With Diodes

Abstract

In this brief, a novel trench clustered insulated gate bipolar transistor (TCIGBT) is proposed and investigated by the simulation. In comparison with the conventional TCIGBT, the p-well region is connected to the cathode through two integrated series diodes and a field stop structure is utilized. In the blocking state, the anode voltage is sustained by the p-well/n-drift junction, which makes the breakdown voltage (BV) independent on the dose of n-layer region, eliminating the contradictionbetween theBV and ON-state voltage appearing in the conventional trench insulated gate bipolar transistor (TIGBT). Accordingly, the ON-state voltage can be reduced by increasing the dose of n-layer region. In the ON-state, the electron quasi-Fermi potential of intrinsic drain is clamped at approximately 0.7 V, so that the saturation current is effectively decreased. The results from TCAD simulation indicate that under the same level of BV of the conventional TIGBT the ON-state voltage and saturation current of the proposed device are decreased by 33.6% and 66.6%, respectively. Moreover, a better tradeoff between the turnoff energy loss and ON-state voltage is achieved, i.e., with the same ON-state voltage of 1.29 V, the proposed device shows an improvement of 51.9% in turn-off energy loss.